<template>
  <h3>
    App
    <button @click="handleClick">child +1</button>
    <hr/>
    <Child/>
  </h3>
</template>

<script>
import Child from './Child.vue'
export default {
  name: 'App',
  components: {
    Child
  },
  methods: {
    handleClick() {
      // !#3
      this.$bus.$emit('addCount', 3)
    }
  }
}
</script>